1. Field of the Invention
The present invention relates to an information carrier for high-density storage, in particular for the storage of video signals, in which the information is provided on both sides of the carrier and stored in the form of a beam-reflecting surface structure which is covered, in each case, by a layer of translucent material.
2. Description of the Prior Art
An information carrier of the type mentioned above is known in the art, for example reference may be taken to the German published application No. 2,341,338, which corresponds to the British Pat. No. 1,446,009 of Aug. 11, 1976 and the Australian Pat. No. 5,974,573 of Mar. 6, 1975. This prior information carrier comprises two separate discs of transparent material which are connected together by an intermediate layer and having their respective sides provided with a beam-reflecting surface structure each of which faces the other. With this structure, the information is read by an optical scanning beam which penetrates from the outside through the transparent carrier layer to the beam reflecting surface, where the beam is reflected and modulated according to the profile of the beam-reflecting surface. Here, the thickness of the transparent carrier layer is not particularly critical because the scanning beam is focused as precisely as possible in the information plane. However, considerable demands are made on the homogeneity of the transparent carrier material and in this respect certain difficulties arise in the production of such information carriers because material residues, called "tags", stick to the pressing die and cause corresponding fault zones in the information carriers which are made from these dies. Other material discrepancies are caused by internal material stresses, bubbling or other harmful phenomena which arise during the production process.